1. Field of the Invention
The present invention relates to a structure of a motor section of a working vehicle including a hood covering the motor section and defining an air intake opening in an upper surface thereof, an air-cooled engine mounted in the hood and having a vertical output shaft, a fan disposed above the engine to draw in ambient air, an air guide cover for guiding the air to the cylinder head of the engine and a carburetor disposed laterally of the cylinder head, and a muffler disposed below and adjacent the carburetor.
2. Description of the Related Art
In a conventional structure of a motor section of a working vehicle such as a riding type lawn mower, the muffler is usually surrounded by a muffler cover to stop heat of the muffler reaching other devices arranged around the engine. Consequently, this structure has the drawback that grass particles and dust entrained by engine cooling air tend to accumulate on an upper surface of the muffler cover. Further, in summertime, for example, radiant heat of the muffler tends to pass through the muffler cover to produce a high temperature condition in an engine room. As a result, the carburetor becomes overheated, and particles of air mixed into a fuel are thermally expanded to form bubbles. This may cause a vapor lock, hampering proper fuel supply.
It is conceivable to change position of the muffler in order to overcome the above inconveniences, i.e. to avoid heating of the carburetor due to the radiant heat of the muffler and accumulation of grass particles and dust on the muffler cover. However, this would necessitate rearrangement of the devices associated with the engine inside the hood. Such a rearrangement would involve an extensive change in design.